According to the traditional view, long-term heavy smokers are a high-risk group for lung cancer. This is certainly not wrong, and it is important to be alert to the occurrence of lung cancer in such people, especially those who are over 40 years old. However, does this mean that not smoking means that lung cancer is far away? In fact, smoking is only one of the risk factors for lung cancer, not all of them. The occurrence of lung cancer is also closely related to atmospheric pollution, and in 2014 the World Health Organization announced that PM 2.5 is a serious carcinogen that is as harmful as tobacco. In China, the rate of lung cancer in rural areas is approaching that of urban areas, which also suggests the impact of air pollution. This means that even if you don’t smoke, you are not safe from the threat of lung cancer. As the environment changes, the disease spectrum changes. Previously, squamous carcinoma was the first in the classification of lung cancer. Now, it is adenocarcinoma of the lung that is in first place. It occurs more often in women who are non-smokers, whereas lung cancer was previously thought to be the exclusive preserve of men. The reason why women are increasingly developing lung cancer is the result of a number of factors. Young and middle-aged women’s long-term exposure to high-temperature fumes while cooking in the kitchen increases their risk of lung cancer by two to three times. Women’s estrogen levels are naturally higher than men’s, and this difference increases their susceptibility to lung cancer. Women are also often the victims of “secondhand smoke”. Studies have shown that if a husband and wife live together in a household where the husband smokes and the wife does not, the wife is one to three times more likely to get lung cancer than the husband. At the same time, the more the husband smokes, the greater the chance of lung cancer in the wife. A characteristic of lung cancer in China is that the age of patients is relatively low, mostly around 60 years old, which is 10 years younger than the United States and Europe, which has a greater impact on patients’ lives and families. In clinical practice, the occurrence of lung cancer among 20-30 year olds is also becoming more and more common, which is undoubtedly a huge blow to patients’ families. So, what should be done to cope with it? The most effective measure is regular health checkups. For high-risk groups, especially smokers, low-dose spiral CT for lung cancer screening should be done once a year after the age of 40. Early detection and early diagnosis are necessary to get the best chance of treatment.